Diesel compression ignition engines



May I, 1956 v. R. GROSS DIESEL COMPRESSION IGNITION ENGINES Filed April2, 1952 f I; M MM n WW t /w v a n i 6 United States Patent 2,743,711DIESEL COMPRESSION IGNITION ENGINES Victor R. Gross,Stuttgart-Unterturkheim, Germany, as-

signor to Daimler-Benz Aktiengesellschaft, Stuttgart- Unterturkheim,Germany Application April 2, 1952, Serial No. 280,009

Claims priority, application Germany April 5, 1951 11 Claims. (Cl. 123-32) This invention relates to a diesel compression ignition enginehaving a precombustion chamber, into which the fuel is injected andwhich is connected to the main combustion chamber by means of anoverflow channel.

In diesel engines of this type there frequently occurs the phenomenoncommonly referred to as knocking, which, especially while runningslowly, will imply palpable inconveniences.

One principal object of the present invention is to eliminate suchknocking with means as simple and. eflicient as possible.

According, one feature of this invention substantially consists inusing, in the precombustion chamber, insertion members which extend atleast beyond the middle axis of and across said precombustion chamber oracross the way of the fuel jet and which are preferably constructed aspin-like members.

It has been proved that by these means the knocking phenomenon of theengine may be practically completely eliminated or may be reduced to adegree no longer felt inconvenient. The disposition of pins or bridges,which form the insertion members, thereby olfers the further advantageof particular simplicity, since such pins or bridges may be inserted insimple bores or openings of the precombustion chamber wall and may beprovided subsequently in precombustion chambers already existing.

Furthermore, particularly in the case of small engines, a single pinwill be sufiicient to give the required result. Also several pins orbridges may be provided, which are disposed in parallel or on difierentlevels, preferably crossing one another so as to form a gratelike ortrellis-like insertion assembly crossing the direction of the way of thefuel jet.

The accompanying drawings illustrate several embodiments of thisinvention,

Fig. 1 shows a longitudinal section through a precombustion chamberhaving such pins or bridges inserted,

Figs. 25 are cross sections illustrative of various ways of disposingthe insertion members, Fig. 2 representing a section as taken along theline 22 of Fig. 1,

Fig. 6 is a longitudinal section through a precombustion chamber ofdilferent construction, and

Fig. 7 is a cross section as along the line 7-7 of Fig. 6.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts and moreparticularly to Figures 1 and 2, reference numeral 10 designates thecylinder head which may be of the water-cooled type. A precombustionchamber 12 which is formed by a tube 11 is provided in the cylinder head10. The precombustion chamber 12 consists of an enlarged part 12aadjacent to the injector nozzle and a channel-like chamber part 12bextending towards the main combustion chamber, which channel-likechamber part is connected to said chamber part 120 by means of a jetlike passage. The fuel is injected through the enlarged part 12a in thedirection of the channel-like part 12b, whereby such an injectionpressure may be used as to make the fuel, such as in starting, suitablyenter from across the precombustion chamber directlyinto the maincombustion chamber.

Now accordingto this invention there are provided pin-like insertionmembers 14 or 15, suitably located on or adjacent to the place wheresaid enlarged chamher part 12a passes over into said channel-likechamber part 12b, which insertion members are disposed across thelongitudinal axis of the path of the fuel jet and are inserted in bores16 and 17 of the precombustion chamber wall or tube 11. In theembodiment as illustrated by Figures 1 and 2 three upper pin-likeinsertion members 14 are disposed at intervals and in parallel aboveanother pin-like insertion member 15 crossing the former. According tothe dimensions and the use of the precombustion chamber a differentnumber of insertion pins or bridges may be used. Thus instead of a totalnumber of four pins or bridges more or less of them, eventually onlyone, may be used.

When using two pins, such as pins 14 and 15,'they may be disposedcrosswise as shown in Fig. 3, or in parallel, as illustrated by Fig. 4,extending in the same transversal plane of the precombustion chamber.

In the construction as represented by Fig. 5 it is assumed that the pinsor bridges are disposed in three superposed levels one above the other,the top level being formed by a transversal pin or member 14, the secondlevel by two pins 18 disposed in parallel and at an angle relative topin 14, the third level being formed by another pair of pins 19 disposedlikewise at an angle to the pins of the two other ranges.

In the embodiments as illustrated by Figures 6 and 7 the pins 14, 15 and14" are equally disposed in three superposed levels, the pins 14' and14!" extending in parallel. Said pins are inserted in that case in crossbores of an insertion member 11 which lines the channel-like chamberpart 121), while each of the pins 14' and 14" engage in recesses of pin15.

Instead of a cylindrical shape the pins or bridges may be constructedwith any other cross section, e. g. a square one. However thecylindrical construction of the insertion pins will, as a rule, presentparticular advantages as to the manufacture.

This invention is not restricted to the embodiments as illustrated, butis appropriate for all types of diesel (compression ignition) engines,being however especially important for such vehicle diesel engines asare working within a broad range of different numbers of revolutions aswell as of output.

What I claim is:

1. A diesel internal combustion engine of the injection type comprisinga main combustion chamber, a precombustion chamber having an enlargedand a reduced cross sectional portion, an injection nozzle opening intosaid enlarged cross sectional portion, and several pinlike insertionmembers extending across said precombustion chamber, said insertionmembers being located exclusively in a region intermediate said enlargedand reduced portions thereby leaving a free enlarged portion of saidprecombustion chamber having an axial length of at least about half theaxial distance from said injection nozzle to said main combustionchamber.

2. A diesel engine according to claim 1, in which the insertion membersare disposed side by side like a grate.

3. A diesel engine according to claim 1, in which the insertion membersare disposed crosswise with respect to each other.

4. A diesel engine according to claim 1, in which the insertion membersare disposed crosswise on different levels.

'5. A diesel-injection internal combustion engine cornprising a maincombustion chamber, a prechamber connected with the main combustionchamber, a sleeve-like insert member at least partially forming theprechamber wall and providing a communicating passage between saidprech'arnber and said main combustion chamber, transverse bores in theinsert member within the region of transition from said prechamber intosaid communicating passage, cylindrical pin-shaped insertionmembers'incording to claim 5, wherein said insertion members aredisposed crosswise on different levels.

8. A diesel-injection internal combustion engine ac cording to claim 5,wherein said insertion members are disposed crosswise and are in contactwith each other.

9. A diesel internal combustion engine of the injection type comprisinga main combustion chamber, a precombustion chamber having an enlargedand a reduced crosssectional portion, an injection nozzle opening intosaid enlarged cross-sectional portion, and at least one pinlilteinsertion member extending across said precombustion chamber, saidinsertion members being located exclusively in a region intermediatesaid enlarged and reduced portions thereby leaving a free enlargedportion of said precombustion chamber having an axial length of at leastabout half the axial distance from said injection nozzle to said maincombustion chamber.

10. A diesel internal combustion engine of the injection type comprisinga main combustion chamber, a precombustion chamber having an enlargedand a reduced cross-sectional portion, an injection nozzle opening intosaid enlarged cross-sectional portion, and at least one pinlikeinsertion member extending across said precombustion chamber, saidinsertion member being located in a region intermediate said enlargedand reduced portions thereby leaving a free enlarged portion of saidprecombustion chamber having an axial length of at least about half ofthe axial distance from said injection nozzle to said main combustionchamber and providing for impingement of the injected fuel jet on saidinsertion member only after traversing said axial length.

11. A diesel-injection internal combustion engine according to claim 9,in which the pin-like insertion member is of cylindrical form, incombination with a sleevesha'ped insert member forming at least in partthe wall of the prechamber and having a transversely-extending bore inwhich the pin-like insert member is inserted.

References Cited in the file of this patent UNITED STATES PATENTS1,329,797 Raabe Feb. 3, 1920 FOREIGN PATENTS 384,496 Great Britain Dec.8, 1932

